Field of the Disclosure
The present disclosure relates to a technique for generating intermediate data by using a plurality of processing units.
Description of the Related Art
In the rasterization based on print data (page description language (PDL) data) described in a page description language, intermediate data described in an intermediate language is generated based on PDL data and then the intermediate data is rasterized into a raster image. Japanese Patent Application Laid-Open No. 2012-16842 discusses a technique used by a printer mounting a multi-core central processing unit (CPU) having a plurality of processor cores to parallelly perform the rasterization on different pages. More specifically, each processor core is sequentially assigned a rasterization target page, generates intermediate data based on the PDL data of the assigned page, and then rasterizes the intermediate data to generate a raster image of the page. Then, the raster image is transmitted to a printer engine and then printed.
In a conventional printer, a plurality of processor cores performs the rasterization for respective different pages. Therefore, the conventional printer performs the following control to cause the order of pages to be printed to coincide with the order of pages of the PDL data. Even when one processor core first completes the rasterization of the following page, the one processor core waits until the other processor core completes the rasterization of the preceding page and the transmission of a raster image to a printer engine, and then transmits a raster image of the following page to the printer engine.
More specifically, in the conventional printer, the raster image resulting from the rasterization of the following page is continuously stored in a memory until the raster image of the preceding page is generated. Therefore, the printer requires an amount of memory sufficient for storing these raster images.